In Reply to: 5-speed owners, does your car do this? (Wierd...) posted by Tim Collins on November 04, 1999 at 00:40:10:
This mpg indicator is there to give you a fairly accurate mpg reading only while driving AT A STEADY PACE (on the trottle), not while cruising (idle).
Under acceleration the needle swings towards the right of the scale, and the mpg readings are completely unreliable; they can only serve as an indication of how hard you're accelerating at that moment.
Note the difference between the readings at idle and at full acceleration: at idle the needle is to the right, out of view; this IS NOT a reading. At full acceleration the needle is also at the right, out of view; this IS a reading, however out of scale.
So at idle while cruising or parked, the needle should go to the right, out of view, giving NO indication.
The mpg indicator is actually a direct indication of how much fuel the Motronic is injecting.
It will not give you an indication at idle. After all, who wants to know his fuel consumption at idle?